Effect of dietary fat and environment on lipogenesis by large white breeder turkeys.

An experiment was conducted to evaluate the effects of either a low-fat (8% of total calories) or high-fat (47% of total calories) diet on Large White breeder females maintained at a constant (21 C) or a cyclic temperature regimen (12 to 27 C). Each diet was fed to 32 hens individually caged in the cyclic condition and 46 in the constant condition. Energy consumption, reproductive performance, and in vitro lipogenesis were monitored for hens subjected to both temperature and dietary treatments. Hens consumed more (P less than .05) dietary energy when maintained at a constant temperature or when fed the low-fat diet. Hens also produced more (P less than .05) eggs when maintained under cyclic temperature conditions, although this observation was tempered by the fact that fewer hens were broody. More (P less than .05) of the fertile eggs from hens held at the cyclic temperature resulted in live poults. The high-fat diet decreased (P less than .05) in vitro lipogenesis in hens and may also decrease the maintenance energy requirement by providing a preformed fatty acid pool for egg lipids. The high-fat also decreased (P less than .05) liver lipid and the activities of fatty acid synthetase and malic enzyme.